Recent advances in increasing the speed of a semiconductor device having a semiconductor chip such as a memory chip or a logic chip, increasing the operating ratio of a semiconductor chip, and the like have made semiconductor chips more prone to generating heat. Therefore, the heat must be expelled outside the semiconductor device. In a ball grid array (BGA) type semiconductor device, however, many organic members having poor heat transfer properties are used, making it difficult to expel heat from the semiconductor chip of the semiconductor device into the atmosphere.
With the semiconductor device described in Patent Document 1 (Japanese Unexamined Patent Publication No. 2000-68403), a package housing a semiconductor chip and comprising a wiring substrate and a sealing body is mounted on a mounting substrate. A plurality of heat-dissipating solder balls (solder bumps) are disposed in a central region of the mounting substrate-connecting surface (substrate-connecting surface) of the wiring substrate constituting the package of the semiconductor device for holding the semiconductor chip (semiconductor element). Because the semiconductor device disclosed in Patent Document 1 has a configuration in which heat from the semiconductor chip is transferred to the plurality of heat-dissipating solder balls, the heat generated by the semiconductor chip is transferred through the heat-dissipating solder balls to the connected mounting substrate, and expelled from the mounting substrate to outside the semiconductor device.